Different TP and miles on different days ?

Was looking online at VS site to book UC return JFK to LHR.
Booking the same Friday in September:

If I get the 8am Newark to LHR flight its 10,374miles + 10TP round trip. cost $3722, inc taxes
but:
select the 9.20pm flight from JFK its 12,103 miles and 11 TP's (?) Cost $5308 inc taxes.

Either JFK is almost 1000 extra miles from NYC than Newark (nope) or the website is broken. And where's that extra eleventh TP from?!

Different fare class?

Good guess. The JFK one is switched to a D outbound, Z return; whereas the Newark a.m are both Z's.

Any special advantage to a D, rather than a Z? It's a lot more money.

You would get a CDC with a 'D' (on the D leg only though and as this isyour LHR - NYC leg you would alos get DTCI).

You get an extra TP plus some extra miles as a D gets 200% of miles rather than 150 for a Z (based on being FC red)

More TPs and miles which many value. Increased flexibility of ticket which may, or may not, be of value to you. Plus a CDC.

D qualifies for the CDC transfer whereas the Z doesn't.

Check "The Toolbox" and "Fare Codes" for the fare code differences.

[Neil]

More flexible in terms of changes. Qualifies for a CDC. Earns more miles and TP's.

okay, so I'd get a free CDC out from Manhattan to JFK on my D fare, plus some higher miles (I am AU) and an extra TP for this one D leg. and pay $1600 more for that.

I could try for a D in both directions, though I don't need the CDC returning, as I fly in to LHR on a connecting flight.

Doesn't seem that great a deal, but the Z's seem to be unavailable on the evening flights, the website is only offering D's on any evening flight out of JFK that day. Think I'll wait and see what frees up.

[Neil]

The biggest advantage of the D fare code compared to a Z is that it is more flexible/less restricted in terms of changes.

The closer the flight gets the less chance of any cheaper fare codes becoming available. The Z fare had advance purchase restrictions of 21 days for example.

The biggest advantage of the D fare code compared to a Z is that it is more flexible/less restricted in terms of changes.

ok thanks Neil, got it. we'll see what appears.
sometimes Orbitz is a lot cheaper than VS themselves for these tickets.